While booting a computing device, a basic input-output system (BIOS) of the computing device is initiated. When the BIOS is executed, a power-on self test (POST) is performed to make sure that hardware of the computing device can be normally operated. When the POST is finished, the BIOS tries to read a sector of the hard disk which is called the master boot record (MBR). The data in the MBR are loaded into a memory to be executed, and then data provided by an operating system (OS) is loaded to enter the operating system.
If errors occur in the BIOS, the BIOS stored in a flash memory of the computing device needs to be recovered to boot the computing device normally. However, it is difficult or problematic to recover the BIOS if main program codes of the BIOS are damaged. Thus, the computing device needs to be sent back to the original manufacturer to recover the BIOS.